A false report on appearance inspection of a semiconductor device is prevented by suppressing variation in surface state of an electrodeposited gold electrode. In formation of an electrodeposited gold electrode, an electrodeposited gold electrode comprised of a plurality of electrodeposited gold layers in the stack is formed by alternately repeating a step of performing energization between an anode electrode and a cathode electrode provided in a treatment cup of a plating apparatus to cause crystal growth of an electrodeposited gold layer (energization ON), and a step of performing no energization between the anode electrode and the cathode electrode (energization OFF). Consequently, even if aging variation occurs in composition of the plating solution, variation in surface state of the electrodeposited gold electrode is suppressed, and a surface state with a surface roughness of, for example, about 0.025 rad can be maintained.
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1. A method of manufacturing a semiconductor device, comprising the step of: (a) forming an electrodeposited electrode over a main surface of a semiconductor wafer provided in a plating solution bath with an anode electrode in a treatment cup, wherein (a) includes the steps of: (a1) performing energization where current continuously flows for at least 20 sec. between the anode electrode and the semiconductor wafer to cause crystal growth of an electrodeposited gold layer over the main surface of the semiconductor wafer, and (a2) performing non-energization where the current does not flow for at least 2 sec. between the anode electrode and the semiconductor wafer, and wherein the step (a1) and the step (a2) are alternately repeated a plurality of times, and the electrodeposited electrode is formed by repeating the step (a1) directly followed by the step (a2) to form a stack of electrodeposited gold layers which comprise the electrodeposited electrode, and wherein each of the electrodeposited gold layers is 0.5 μm thick.
A method for manufacturing a semiconductor device forms an electrodeposited electrode on a semiconductor wafer in a plating solution bath using an anode. The process involves alternating between energization and non-energization steps. Energization means current continuously flows for at least 20 seconds between the anode and the wafer, causing crystal growth of an electrodeposited gold layer. Non-energization means no current flows for at least 2 seconds. These steps are repeated multiple times, creating a stack of electrodeposited gold layers that make up the electrode. Each gold layer is 0.5 μm thick.
2. The method according to claim 1 , wherein a non-energization time in the step (a2) is 2 to 15 sec.
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and improves control over the non-energization step. The non-energization time, where no current flows between the anode and semiconductor wafer, lasts between 2 and 15 seconds. This non-energization period occurs between periods of energization of at least 20 seconds during which current flows to cause crystal growth of electrodeposited gold.
3. The method according to claim 1 , wherein a non-energization time in the step (a2) is 3 to 11 sec.
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and further refines control over the non-energization step. The non-energization time, where no current flows between the anode and semiconductor wafer, lasts between 3 and 11 seconds. This non-energization period occurs between periods of energization of at least 20 seconds during which current flows to cause crystal growth of electrodeposited gold.
4. The method according to claim 1 , wherein a non-energization time in the step (a2) is 5 to 7 sec.
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and even further refines control over the non-energization step. The non-energization time, where no current flows between the anode and semiconductor wafer, lasts between 5 and 7 seconds. This non-energization period occurs between periods of energization of at least 20 seconds during which current flows to cause crystal growth of electrodeposited gold.
5. The method according to claim 1 , wherein an energization time in the step (a1) is longer than a non-energization time in the step (a2).
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and the energization and non-energization times are balanced. The energization time (current flowing to cause crystal growth of electrodeposited gold) is longer than the non-energization time (no current flow). The energization periods are at least 20 seconds, separated by non-energization periods of at least 2 seconds.
6. The method according to claim 1 , wherein an energization time in the step (a1) is 20 to 60 sec.
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and controls the energization time more specifically. The energization time, during which current continuously flows between the anode and the semiconductor wafer to grow the electrodeposited gold layer, lasts between 20 and 60 seconds. This energization period is alternated with a non-energization period of at least 2 seconds where no current flows.
7. The method according to claim 1 , wherein the electrodeposited electrode includes one of gold, copper, and nickel as a main component.
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and specifies the electrode's composition. The electrodeposited electrode includes gold, copper, or nickel as its primary component. The electrode is formed by alternating energization (at least 20 seconds) and non-energization (at least 2 seconds) steps to create stacked layers, each 0.5 μm thick.
8. The method according to claim 1 , further comprising the steps of: before the step (a), (b) forming a pad electrode over the main surface of the semiconductor wafer; (c) after the step (b), forming an insulating film over the main surface of the semiconductor wafer so as to cover the pad electrode; (d) after the step (c), forming an opening in the insulating film to expose a top of the pad electrode, and (e) after the step (d), forming a seed film over the main surface of the semiconductor wafer, wherein the electrodeposited electrode is formed over the seed film.
The method of manufacturing a semiconductor device involving electrodeposition adds steps before the electrodeposition. First, a pad electrode is formed on the semiconductor wafer's main surface. Then, an insulating film covers the wafer, including the pad electrode. An opening is created in the insulating film to expose the top of the pad electrode. A seed film is then formed over the entire surface, and the electrodeposited electrode (formed by alternating energization/non-energization) is deposited on this seed film. Energization periods are at least 20 seconds, and non-energization periods are at least 2 seconds.
9. The method according to claim 8 , wherein the pad electrode comprises an aluminum film, and the seed film comprises a stacked film including a titanium film and a palladium film formed in order.
This method builds on the previous electrodeposition process, and details the pad and seed film compositions. The pad electrode is made of an aluminum film. The seed film is a stacked film comprising a titanium film and a palladium film, deposited in that order. An insulating film covers the pad electrode, and an opening is made to expose the pad electrode's top. The electrodeposited electrode is then formed over the seed film by alternating energization (at least 20 seconds) and non-energization (at least 2 seconds) to create stacked layers.
10. The method according to claim 1 , wherein the plating solution is stirred by a stirrer in the step (a1), and wherein a direction of stirring by the stirrer is reversed when repeating the step (a1).
This method refines the electrodeposition process with solution stirring. The plating solution is stirred during the energization step (at least 20 seconds). Critically, the direction of stirring is reversed each time the energization step is repeated. The method alternates between this energization step and a non-energization step of at least 2 seconds, repeating them to form the electrodeposited electrode composed of stacked layers, each 0.5 μm thick.
11. A method of manufacturing a semiconductor device, comprising: (a) forming an electrodeposited gold electrode over a main surface of a semiconductor wafer provided in a gold sulfite plating solution bath with a non-gold anode electrode in a treatment cup, wherein (a) includes the steps of: (a1) performing energization where current continuously flows for at least 20 sec. between the anode electrode and the semiconductor wafer to cause crystal growth of an electrodeposited gold layer over the main surface of the semiconductor wafer, and (a2) performing non-energization where the current does not flow for at least 2 sec. between the anode electrode and the semiconductor wafer, and wherein the step (a1) and the step (a2) are alternately repeated, and the electrodeposited electrode is formed by repeating the step (a1) directly followed by the step (a2) to form a stack of electrodeposited gold layers which comprise the electrodeposited electrode, wherein each of the electrodeposited layers is 0.5 μm thick, and the electrodeposited electrode is 3 μm thick, and wherein a direction of stirring the gold sulfite plating solution bath is alternately reversed when repeating the step (a1).
A method for manufacturing a semiconductor device forms a 3 μm thick electrodeposited gold electrode on a semiconductor wafer using a gold sulfite plating solution bath and a non-gold anode. The electrode is formed by alternating energization and non-energization steps. Energization means current continuously flows for at least 20 seconds between the anode and the wafer, causing crystal growth of an electrodeposited gold layer. Non-energization means no current flows for at least 2 seconds. These steps are repeated, creating a stack of electrodeposited gold layers (each 0.5 μm thick). The direction of stirring the gold sulfite plating solution is alternately reversed with each energization step.
12. The method according to claim 1 , wherein the electrodeposited electrode has a surface roughness of 0.025 rad or more.
The method of manufacturing a semiconductor device involves forming an electrodeposited electrode, and the electrodeposited electrode has a surface roughness of 0.025 rad or more. The electrodeposited electrode is formed over a main surface of a semiconductor wafer provided in a plating solution bath with an anode electrode in a treatment cup by alternating energization (at least 20 seconds) and non-energization (at least 2 seconds) steps to create stacked layers, each 0.5 μm thick.
13. The method according to claim 11 , wherein the electrodeposited electrode has a surface roughness of 0.025 rad or more.
The method of manufacturing a semiconductor device involves forming an electrodeposited gold electrode using a gold sulfite plating solution with a non-gold anode, and the electrodeposited electrode has a surface roughness of 0.025 rad or more. The electrode is formed by alternating energization (at least 20 seconds) and non-energization (at least 2 seconds) steps to create stacked gold layers, each 0.5 μm thick, until the electrode is 3 μm thick. The stirring direction of the plating solution is reversed with each energization step.
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January 15, 2015
August 15, 2017
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